The terrorist attacks on 9/11 underscored the vulnerability of the U.S. homeland. In response to those attacks and to protect the homeland, U.S. policy-makers created the Department of Homeland Security (DHS), responsible for homeland security, and its military counterpart, U.S. Northern Command (NORTHCOM), responsible for homeland defense.

However, even with DHS and NORTHCOM’s efforts, threats that pose significant danger to national security continue to emerge. At the forefront of these threats are al-Qaeda’s continued aim of conducting a massive attack on U.S. soil and a significant increase of violence caused by Mexican-based transnational criminal organizations (TCO) over control of ungoverned areas along the U.S.-Mexico border. While the U.S.-led efforts are producing positive results against violent extremists and TCOs, these successes are insufficient to counter growing national security threats.

Using a capabilities-based assessment model as a guide, this paper examines the current operational capabilities of Immigration and Customs Enforcement, Customs and Border Protection, and NORTHCOM. The analysis highlights the capabilities required to combat current and future threats along the southwest border and identifies the gaps between existing and required capabilities. From this analysis, a set of solutions to fill these gaps and leverage existing DoD capabilities is proposed. While not all-inclusive, these solutions provide the U.S. government with a framework to build DHS capacity along the southwest border and better counter the threats of growing instability within Mexico.